一个函数传参一个 slice，先 append 再赋值和另一个函数先赋值再append，哪个会发生变化？

题目来源：字节跳动

答案：

package main
import "fmt"
func BeforeAppend(s []int) []int {
    s = append(s, 1)
    s = []int{1, 2, 3}
    return s
}
func AfterAppend(s []int) []int {
    s = []int{1, 2, 3}
    s = append(s, 1)
    return s
}
func main() {
    s := make([]int, 0)
    fmt.Println(BeforeAppend(s))
    fmt.Println(AfterAppend(s))
}